The Internet has enabled interconnection of different computer networks all over the world. The ability to effectively protect and maintain stable computers and systems, however, presents a significant obstacle for component manufacturers, system designers, and network operators. Email and other electronic communications can be a source of security threats and vulnerabilities, not only through the potential introduction of malware (e.g., via email attachments, etc.), but also from the standpoint of accidental and malicious disclosures of confidential and other sensitive data via email. For instance, email is frequently used to communicate important information, documents, and files between and within organizations. Encryption of the email data, attachments, and/or the data stream over which email data is sent have been used to assist in protecting email content from falling into the wrong hands. In some instances, however, once an email has been sent to a recipient, the sender loses a measure of control over the sent email and its contents. In many instances, the sender then relies entirely on the trustworthiness and vigilance of the recipient to protect and guard against the forwarding of the email contents using unsecure channels or to untrusted or unauthorized third parties.
Like reference numbers and designations in the various drawings indicate like elements.